David and Jeanie Stiles have been helping parents and kids design and build better treehouses for decades. In fact, the husband and wife team from East Hampton, N.Y., has been called America’s first couple of do-it-yourself building projects. They have penned numerous books on the subject, including Tree Houses You Can Actually Build and How To Build Tree Houses, Huts & Forts.

“For kids, it’s all about them having their own space, where they’re the master of their own universe up in the tree,” David says.

To help you and your kids build a better backyard treehouse, the Stiles offer these tips:

Get the kids involved. “We always encourage kids to be ‘hands on’ with the project,” Jeanie says. “Have a big family meeting with the kids and find out what everybody wants and the jobs everyone can do. When kids are involved, they like it more.”

Choose a good spot. You need at least one good tree to build in, and keep in mind the need for an electric extension cord to reach the construction area. Also find a spot that’s least visible from a neighbor’s house.

Pick the right tree. A treehouse can be built in almost any tree as long as it’s healthy and strong enough to support the weight of the building materials and occupants. The best trees, according to David, are banyans, cottonwoods, beech or any large sprawling trees like elms and maples. The perfect tree is 3 to 4 feet in diameter with large horizontal branches 8 to 10 feet from the ground.

“The tree will dictate what the treehouse will look like,” he says. “You look at the tree, and you try to visualize a 6-foot in diameter basketball, which helps you get an idea of what it’s going to take and where the treehouse will go.”

Get it straight. When choosing lumber, make sure each board is straight by holding it at arm’s length and sight down the edges of the board. If you have questions, ask lumberyard employees.

Build a strong platform. “You can build things kind of crazy if you want, but you’ve got to start out with a strong platform that’s level and secure,” Jeanie says. “So put a lot of thought into the base to your treehouse. Once you start building your walls, there’s much more freedom.”

Make it kid-size. “The scale should be to the size of a kid,” David says. “So a good treehouse is hard for an adult to get into, but easy for kids.”